io.debezium.connector.db2.TxLogPosition Maven / Gradle / Ivy
/*
* Copyright Debezium Authors.
*
* Licensed under the Apache Software License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
*/
package io.debezium.connector.db2;
import io.debezium.connector.Nullable;
/**
* Defines a position of change in the transaction log. The position is defined as a combination of commit LSN
* and sequence number of the change in the given transaction.
* The sequence number is monotonically increasing in transaction but it is not guaranteed across multiple
* transactions so the combination is necessary to get total order.
*
* @author Jiri Pechanec
*
*/
public class TxLogPosition implements Nullable, Comparable {
public static final TxLogPosition NULL = new TxLogPosition(null, null);
private final Lsn commitLsn;
private final Lsn inTxLsn;
private TxLogPosition(Lsn commitLsn, Lsn inTxLsn) {
this.commitLsn = commitLsn;
this.inTxLsn = inTxLsn;
}
public Lsn getCommitLsn() {
return commitLsn;
}
public Lsn getInTxLsn() {
return inTxLsn;
}
@Override
public String toString() {
return this == NULL ? "NULL" : commitLsn + "(" + inTxLsn + ")";
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((commitLsn == null) ? 0 : commitLsn.hashCode());
result = prime * result + ((inTxLsn == null) ? 0 : inTxLsn.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
TxLogPosition other = (TxLogPosition) obj;
if (commitLsn == null) {
if (other.commitLsn != null) {
return false;
}
}
else if (!commitLsn.equals(other.commitLsn)) {
return false;
}
if (inTxLsn == null) {
if (other.inTxLsn != null) {
return false;
}
}
else if (!inTxLsn.equals(other.inTxLsn)) {
return false;
}
return true;
}
@Override
public int compareTo(TxLogPosition o) {
final int comparison = commitLsn.compareTo(o.getCommitLsn());
return comparison == 0 ? inTxLsn.compareTo(o.inTxLsn) : comparison;
}
public static TxLogPosition valueOf(Lsn commitLsn, Lsn inTxLsn) {
return commitLsn == null && inTxLsn == null ? NULL
: new TxLogPosition(
commitLsn == null ? Lsn.NULL : commitLsn,
inTxLsn == null ? Lsn.NULL : inTxLsn);
}
public static TxLogPosition valueOf(Lsn commitLsn) {
return valueOf(commitLsn, Lsn.NULL);
}
@Override
public boolean isAvailable() {
return inTxLsn != null && commitLsn != null;
}
}